The Chelsea Critical Care Physical Assessment tool (CPAx): validation and evaluation into the impact of a daily bedside scoring system which grades physical recovery from critical illness.

Abstract

Muscle wasting is a common consequence of critical illness, leading to long-term physical morbidity. Early rehabilitation in the Critical Care Unit (CCU) is now the norm. Guidelines suggest that this rehabilitation should be goal-directed and based on comprehensive assessment of physical function, however there was no tool to assess physical function objectively. The aim was to evaluate the clinimetric properties of the Chelsea Critical Care Physical Assessment tool (CPAx); a tool designed to measure function in critical illness objectively; to explore the patient experience of the CPAx in early rehabilitation, and; to use the CPAx to evaluate common recovery trajectories. This was a convergent mixed methods study. Preparatory work included integration of the CPAx into clinical practice, allowing recording of daily CPAx. Observational cohort studies were completed to determine the validity, responsiveness, and floor/ceiling effect of the CPAx. The database was also used to explore daily functional recovery and to establish the minimal detectable change (MDC) of the CPAx. An eLearning module to teach clinicians how to use the CPAx was developed and distributed with evaluative questionnaires to determine the CPAx’s content validity. Case studies were embedded in the module for inter-rater reliability testing. Grounded-theory methodology with semi-structured interviews was used to explore the patient experience of the CPAx tool in early rehabilitation. The results showed that the CPAx is valid, reliable, responsive, and widely used; however, it is likely to have a ceiling effect after hospital discharge. The CPAx may have a role in goal setting for long-stay patients and help to fill in loss of life narrative after critical illness; however the CPAx is difficult to comprehend in the early days of CCU, which are overshadowed by delirium, sleep deprivation and fatigue. Function and CCU length of stay are closely associated, suggesting that function may influence length of stay.